(Reuters) - Major League Baseball suspended Houston Astros rookie pitcher David Paulino for 80 games without pay after he tested positive for a performance-enhancing substance, the league announced on Saturday.

The 23-year-old elected not to appeal the suspension and began serving his penalty with Saturday’s game against the New York Yankees.

Paulino made his Major League debut last year and joined Houston’s rotation in May this season. He has a 2-0 record with a 6.52 ERA in six starts.

“We are disappointed in the news today regarding David Paulino,” Astros general manager Jeff Luhnow said in a statement.

“We hope this is a one-time incident and something David can learn from as he continues his career. The Astros will continue to fully support Major League Baseball’s Joint Drug Prevention and Treatment Program.”

Paulino could potentially return for the final game of the regular season, but will be ineligible for post-season play should the Astros qualify.